Polycations, such as polylysine, have been used to facilitate delivery of nucleic acids to cell interior. Both in vitro and in vivo applications have taken advantage of this property. See, for example, Gao et al., 1996, Biochem. 35:1027-1036.
Polynucleotides, typically DNA, may be taken into a cell by a receptor-mediated endocytosis pathway, a cellular mechanism which internalizes specific macromolecules. In general, complexes designed to be delivered in this fashion contain nucleic acids encoding the gene of interest and a polycationic agent, which acts as a DNA-binding carrier and both neutralizes the charge on the nucleic acids and condenses it.
Condensation facilitates entry of nucleic acids into cell vesicle systems by simulating a macromolecular structure. For example, polylysine condenses DNA into a toroid or doughnut-like structure. (Wagner et al., 1991, Proc. Natl. Acad. Sci. 88:4255-4259).
Polycations previously utilized for nucleic acid delivery to cell interiors include polylysine, protamines, histones, spermine, spermidine, polyornithine, polyargnine, and putrescine.
All publications mentioned herein are incorporated herein by reference for the purpose of disclosing and describing features of the invention for which the publications are cited in connection with.